Basic CS-Operating System [3i Infotech Placement]: Sample Questions 33 - 35 of 89

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Question 33

Operating System

Describe in Detail


What has triggered the need for multitasking in PCs?


Define Multitasking
  • Multitasking is allowing set to perform more than one computer task at a time.
  • Growth of client server computing is the main driver for multitasking- a server necessarlily must support multiple clients.
  • Modern computing requirements like use of cloud computing, backend processing, web servers etc. are driving this further.
  • Ever-increasing computing power with support for multiple cores/threads, support for virtual memory, increased speed and memory capacity of microprocessors are primary hardware changes supporting growth of multitasking.

Question 34

Operating System

Write in Short

Short Answer▾

What are the sub-components of I/O manager in Windows NT?


  • Network redirector/server
  • Cache systems
  • File systems
  • Network driver
  • Device driver

Question 35

Operating System

Describe in Detail


What are the four layers that Windows NT has in order to archive independence?


Hardware Abstraction Layer

Understanding of Hardware Abstraction Layer
  • HAL or hardware abstraction layer is the logical abstraction between physical hardware and software.
  • Provides a device driver interface allowing communication with hardware.
  • Main purpose is to connect different hardware to the OS- system peripherals.


Define Structure of Kernel
  • The central part of an operating system.
  • Manages main aspects like RAM, memory, CPU scheduling, security etc.
  • Manages communication between the software and the hardware.

Main Tasks of the Kernel

  • Process management
  • Device management
  • Memory management
  • Interrupt handling
  • I/O communication
  • File system


  • The protected subsystems act as mediators between the user-level application and the NT executive.
  • Subsystem allows NT to provide each process a container virtualizing the operating system.
  • Every application runs only in the subsystem for which it was designed- sub-system is determined at launch of application in Windows NT

System Services

Operating System Services
  • System supplies different kinds of services to both the user and the programs.
  • Provides application programs an environment to execute.

Common Program Services

  • User interface
  • Program execution runtime
  • Input/output operations
  • Communication.
  • Error detection
  • Accounting
  • Security and protection

Common User Services

  • Authentication
  • Program execution
  • Protection

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